(A) study on nonlinear control of pulsed plasma thruster for spacecraft attitude contro using lyapunov-based Design

Abstract

Pulsed Plasma Thruster (PPT) for micro-satellite is a system for satellite attitude control as well as orbit transfer and/or maintain. PPT has currently applied to micro satellite because of low thruster. An attitude control of satellite is performed by two mechanisms. One is sensing or detecting the coordinations of a satellite attitude by using sun sensor, star tracker, and earth sensor from sun, star, earth , respectively. The other one is actuating to the spacecraft to compensate its attitude by using a processed sensing data. In accordance with actuators, there are two types of actuator as wheels and thrusters. In this thesis, PPT will be mainly focused on as to thruster for satellite attitude to replace wheels, and according to the trends of thruster field, two types of thruster are developing these day such as chemical thruster and electrical thruster. An electrical thruster has a lot of benefits against some chemical propulsion systems such as total mass reduction, simple control mechanisms, easy control, low power consumption, and highly system reliability including propellant feeding system. Therefore, in this thesis, we studied on optimal and robust control method of PPT energy charge by using Lyapunov-based Design to provide uniform thrust with spacecraft for the purpose of precise attitude control.